Go to Extensions > Select from drop down Extension type- Modules You should see an entry for this Postmen-Connector

From the action menu click install, Wait for installation to complete

Once the connector is installed, Click edit option from the action menu, Enter your Postmen API key and enable the connector to complete the process.

Installation for OpenCart Extension Version 1.5.x

If you don't have it installed, install the Vqmod version for Opencart: > You can download the Opencart version from here and the instructions to install here. To check that the installation was successful you can look in the folder app/vqmod/vqcache , if there are files the installation was successful.